1 Sanic is eqilent to the speed of light (299 792 458 m/s) and it´s inspired by Sonic the Hedgehog. It´s often used by respectable scientists and was first introduced by Albert Einstein.
It´s also not very rare to hear it as an adjective to something that REALLY fast.

"By my estimates, in 2040 our cars will go at approximately 0,5 sanics."
"Dude, that car went sanic fast!"

Sanic usually refers to ear rape or other forms of extremely loud spam. Derives from the YouTube video "HOW 2 DRAW SANIC HEGEHOG" in which the uploader draws an extremely mediocre Sonic the Hedgehog while a messed up version of music from the Green Hill Zone stage.
Spinoffs include "HOW 2 DRAW MAREO BROTER", "HOW 2 DRAW: HOMRE SIMSON", and "HOW 2 DRAW LEFEND ZEDLA"

Guy 1: This kid was mic-spamming Sanic in our Vent room.
Guy 2: What a noob.

When a moment or memory that is fantastic, requires a better word than funny; but you don't want to sound dumb by continuously adding so's in front of it. (you know you've been in this situation before)

Also needing a better word than hilarious.

Can also be used in replacement for the word insane, but only on rare, necessary occasions.

pronounced (SAY~nick)

Oh my god! That day was so freaking SANIC!!
I like that guy, he's totally sanic.